title: Synthesis of the core ring system of the yuzurimine-type Daphniphyllum alkaloids by cascade condensation, cyclization, cycloaddition chemistry.
abstract: Addition of hydroxylamine to substituted 4-chlorobutanals gives intermediate nitrones that undergo tandem cyclization and then intramolecular dipolar cycloaddition to give the core ring system of the yuzurimine-type natural products. Ring-opening of the isoxazolidines gives amino alcohols that can be converted to 1,3-oxazines, representing the tetracyclic core of alkaloids such as daphcalycic acid and daphcalycine.
authors.affiliation: Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK. i.coldham@sheffield.ac.uk
authors.forename: Iain
authors.initials: I
authors.lastname: Coldham
authors.forename: Luke
authors.initials: L
authors.lastname: Watson
authors.forename: Harry
authors.initials: H
authors.lastname: Adams
authors.forename: Nathaniel G
authors.initials: NG
authors.lastname: Martin
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry*; D000605:Amino Alcohols / Q000737:chemistry*; D003500:Cyclization; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D010078:Oxazines / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D000470:Alkaloids; D000605:Amino Alcohols; D006576:Heterocyclic Compounds, 4 or More Rings; D010078:Oxazines; C474769:daphcalycine